1. Field of the Invention
The present invention relates to a wall-mounted type microwave oven, and more particularly, to a wall-mounted type microwave oven having a lighting device to illuminate kitchen areas disposed therebelow.
2. Description of the Related Art
Generally, a wall-mounted type microwave oven is mounted on a kitchen wall over a gas oven, and not only carries out a cooking operation, but also exhausts gas and fumes generated from the gas oven disposed below the wall-mounted microwave oven.
As shown in FIG. 1, such a wall-mounted type microwave oven includes an oven body 1, which defines an outer contour of the microwave oven. The oven body 1 has a cooking chamber 1a and an electric component compartment 1b on a left side and a right side, respectively, of the inside thereof, which are isolated from each other. An exhaust flow path 1c is defined between outer surfaces of the cooking chamber 1a and the electric component compartment 1b and the oven body 1 to allow gas and fumes generated from a gas oven (not shown) disposed below the oven body 1 to be exhausted therethrough. The exhaust flow path 1c is disposed around the cooking chamber 1a and the electric component compartment 1b. A bottom panel 1d of the oven body 1 is provided at respective opposite sides with intake ports 1e so as to allow the gas and fumes existing below the oven body 1 to be introduced into the oven body 1 therethrough. The oven body 1 is provided at an upper portion thereof with an exhaust fan 1f to discharge the gas and fumes, introduced into the oven body 1 through the intake ports 1c and an exhaust flow path 1c, to an outside.
A pair of lighting devices 2 is provided in the exhaust flow path 1c below the cooking chamber 1a and the electric component compartment 1b to illuminate kitchen areas disposed below the oven body 1.
As shown in FIG. 2, each of the lighting devices 2 includes an opening 3 formed at the bottom panel 1d of the oven body 1 to allow light from the lighting device 2 to be emitted downward therethrough, a lamp housing 4 mounted on the bottom panel 1d to cover the opening 3 and having a lamp 4a supported by an inner wall thereof, and a window bracket 5 provided in the opening 3 and having a transparent window 5a thereon.
The lamp housing 4 is formed in a box shape with one open side facing the opening 3. Left wall 4b and right wall 4c of the lamp housing 4 are formed with a coupling hole 4d and a first coupling hole 4e coupling the lamp housing 4 to the bottom panel 1d. 
The bottom panel 1d is provided at respective opposite ends of the opening 3 with first and second support pieces 6 and 7, which are extended upwardly to support the left and right walls 4b and 4c of the lamp housing 4. The first support piece 6 corresponds to the left wall 4b of the lamp housing 4 and includes a coupling protrusion 6a to be fitted into the coupling hole 4d of the lamp housing 4, while the second support piece 7 corresponds to the right wall 4c of the lamp housing 4 and includes a second coupling hole 7a into which a screw 9, passed through the first coupling hole 4e of the right wall 4c is tightened. The second support piece 7 is provided with a third coupling hole 7c below the second coupling hole 7a, which corresponds to a fourth coupling hole 5b of the window bracket 5, and the second support piece 7 is provided with a rib 7b which is extended inwardly.
The window bracket 5 is provided at one end thereof with a pair of hanger protrusions 5c hanging on the first support piece 6, and the window bracket is provided at the other end with a fastening portion 5d, which is adapted to be in contact with the rib 7b of the second support piece 7 and has the fourth coupling hole 5b of the second support piece 7 corresponding to the third coupling hole 7c. 
An operation of assembling the lighting device will now be described. First, the window bracket 5 is inserted into the opening 3 of the bottom panel 1d, and the pair of hanger protrusions 5c of the window bracket 5 is hung on the first support piece 6. Further, the coupling protrusion 6a of the first support piece 6 is fitted into the coupling hole 4d of the left wall 4b of the lamp housing 4. The lamp housing 4 is rotated toward the second support piece 7 about the coupling protrusion 6a until the right wall 4c of the lamp housing 4 comes into close contact with the second support piece 7. Thereafter, the screw 9 is tightened into the second coupling hole 7a of the second support piece 7 through the first coupling hole 4e of the lamp housing 4 to fix the lamp housing 4 to the bottom panel 1d. The window bracket 5 is rotated about the hanger protrusions 5c until the fastening portion 5d of the window bracket 5 comes into contact with the rib 7b of the second support piece 7. Subsequently, the screw 9 is tightened into the third coupling hole 7c of the second support piece 7 through the fourth coupling hole 5b of the fastening portion 5d to fix the window bracket 5 to the bottom panel 1d, thereby completing the assembly of the lighting device.
However, since an assembling operation of the lighting device 2 of the conventional wall-mounted type microwave oven requires that two screws 9 be tightened in order to couple the lamp housing 4 to the bottom panel 1d of the oven body 1 and to couple the window bracket 5 to the bottom panel 1d, manufacturing cost and manufacturing time are increased due to an increase in a number of the screws 9 used, thereby deteriorating productivity.